In 1990 DJ Stretch Armstrong and Bobitto Garcia debuted their college radio show on Columbia University’s WKCR (89.9FM) in NYC and left an indelible mark on the culture. The show, which ran until 1998, helped launch the careers of many of hip-hop’s biggest stars—including The Notorious B.I.G., Jay-Z, Nas, Big Pun, the Wu-Tang Clan, DMX, Cam’ron, Mobb Deep, Big L and Fat Joe, among others.

XXL compiled 20 of the show’s more memorable freestyles, you can check ‘em out over here.